Felipe Massa admits that Williams still has to make a big leap if the Grove team is to challenge Mercedes and Ferrari in 2016.

The team finished third in the constructors’ championship in 2014 and again last year, but Massa acknowledges that the next step is even harder, and that downforce is the key.

“Both seasons were really, really good, but we want more,” Massa said at the Autosport International show. “We know that to fight with these teams in front, Mercedes and Ferrari, you need to do amazing improvements from one year to the other. That’s the way it is. Especially when you look at those teams, they have a lot more opportunities, a lot more money, a lot more budget to put in the car, which we know makes an effect at the end.”

Massa is proud of the progress that the team had made since he joined in 2014.

“I could feel that I was important as well for this improvement, the job we all made together. The work that everybody put together I feel really that I was inside this improvement, and I feel really proud.

“Actually, we want more. It’s impossible to be so happy when you finish third in the championship. We’re fighting teams that are much bigger than us, and we know it’s not easy to be in front of them. We were in front of many big teams, and that’s great, but we want more.

“McLaren, they had a really big problem [last] year, they were struggling a lot. But I think Red Bull showed that we really beat a team that’s much bigger, a team that won many championships in the very near past. We were not far away compared to Ferrari as well, but they were better. But we’re pushing hard for 2016. I hope we can do better than what we did until now.”

Massa made it clear where the biggest gains could be found: “The most important think we need to improve is the aerodynamics of the car. We need to give the car more downforce, so we need to improve this area compared with the teams we are fighting with.

“I would say the engine we are using is a similar engine to [the works] Mercedes, which is the best engine in F1, but Ferrari caught up really a lot. I don’t know how much better is the Mercedes compared to Ferrari, but Ferrari is very, very close, that’s why they improved massively as well.

“But I would say maybe where we need to improve more is on the aerodynamics, which is what we’re working on, maybe already from the middle of last year until now. I hope we can see some improvements in this area.”

Felipe praised team mate Valtteri Bottas, stressing that the fact that they like the same things from a car is a big plus.

“We respect each other in a good way. I think we work together with the team in a proper way, which definitely helps for the position at the end. It’s also thanks to the work that both of us are doing for the team, going to the factory, the simulator, but also pushing the team for not so different ideas.

“I think we feel more or less similar things on the car. I think Valtteri is getting more experience since we started until now, so he grows a lot in terms of experience, which is great. I’m really happy to work with him.”